About the Wren - as we start to build some.

History of the Wren

We have always loved this dainty 0-4-0 saddle tank locomotive. It was the first 16mm model offered by Wrightscale; 190 models later we are about to produce a new batch. Creating these has always been a learning experience. The current batch is the 4th iteration,  we are not afraid to modify and improve as we go along. The new batch will feature a revised cylinder block. The model is now that bit closer to an accurate minature of the real thing. Working steam models of the Wren have been offered in various scales. Experienced constructors in the smaller scales, though, have always regarded it as a difficult engine and have modified their models to make costruction easier, to the point where the 'model' becomes a 'pastiche' - no harm in such, but when they depart too far from the original, something is lost.   

16mm model 0-4-0 Wren made by Wrightscale based on Kerr Stuart No 4560. It incorporates a number of improvements which were made after an initial batch of models.

 Kerr, Stuart and Co Ltd

The Wren was just one of the classes of narrow gauge locomotive produced by Kerr, Stuart and Co Ltd of Stoke on Trent, Staffs. With their good Scots names, you will not be surprised to learn that the company, then a partnership, originated in Glasgow. James Kerr and John Stuart acted as agents for other manufacturers. In 1892, they took over the California Works in Stoke and went into manufacture. Their ‘unique sales proposition’ was narrow gauge, built partly off-the-shelf and then customised to order. Kerr Stuart also produced rolling stock. Until then, if users wanted speedy delivery of narrow gauge locomotives, they had to buy what was available second-hand. 

Another view of the Wrightscale Wren (new type) The most common livery for the prototype was black or green

 The Wren class shows many typical Kerr Stuart design features. It was a company habit to incorporate features from one class in another, and so, for example, side tank locomotives often had variants with saddle tank or tenders. Other classes included Midge and Skylark and the more military sounding Tattoo and Waterloo, not to mention the Darwin and Brazil classes. After World War 1, the company produced standard gauge locomotives. See below.

More Wrens were sold than any other model. Although it was not the smallest locomotive Kerr Stuart built, with a weight of only 4 tons (Imperial) 3 hundred weight in steam, it deserved the name of ‘Wren’.

Wren Development

Kerr Stuart No 850 was an 0-4-0 saddle tank built to the gauge of 2’ 1 ¾ “ It was constructed in 1903 for the Southend Gas Company. She appears to have been the prototype for the ‘Buya’ class – which was usually 3’/75cm. She was also the pattern for a ‘standard type of engine to be called Wren’ (Instructions from the London Office to Stoke on Trent on 1^st February 1905.) No 850 was, thus, also a fore-runner of the Wren.

Kerr Stuart No 888 was Wren no 1, delivered to the Admiralty in March 1905. It was gauged at 2’6”. For Wrens of a more narrow gauge, modifications were needed. In order to fit the firebox within the frames of a 2’ gauge locomotive, the boiler and firebox, as used on no 888 had to be redesigned. In all, 132 were built to 2’ gauge and eleven to 60cm gauge. Although I often write as if 2’ (60.1cm) gauge and 60cm are interchangeable, some modification was necessary if one were to be used on the other track. 2’ gauge wheels would be a ‘tight fit’ on 60cm.

Maker's photograph of No 2462 'new type' Copyright Courtesy of Armley Museum, Leeds. It has Hackworth valve gear, and it is on the 'new type' that our models are based. The batch of models on the Wrightscale stocks will include a more accurate cylinder block, closer to the original

Early locomotives had Stephenson’s links – and are known as ‘old’ type. After K,S 2423 the ‘new’ type was introduced with outside Hackworth valve gear (and attendant modifications) although some old types continued to be ordered. KS No 2458 of 1915 appears to have been the first of this kind. The boiler had to be raised slightly to accommodate the reversing shaft in its new position.

To my mind, though this is personal, I think that the ‘new type’ Wren has a lighter and more elegant appearance.

Very early Wrens had one-piece cast steel wheels. There are obvious advantages to supplying the locomotives with tyres and so most ‘old’ and ‘new’ types went over to cast iron wheel centres with steel tyres.

AnotherWrightscale model construction number 256

 

There were usually a few ‘Wrens’ on the stocks in the factory – typically, they were built in batches of six but were not finished until the gauge the customer required was known. Some orders were for a gauge as small as 1’6 1/8” and the firebox had to be raised (among other alterations). Others were for 915mm gauge (36 ½”). 

'Indaya' Kerr Stuart No 1041. Copyright Courtesy Armley Industrial Museum This 'old type' Wren has been modified for oil-burning and for tramway running. It has Stephenson's links.

Coal was the standard fuel for these little steam engines, but not invariably. Kerr Stuart no 909 (1905) had steel trellis fitted to the bunkers for holding wood. In 1908, nos 1041 and 1042 were supplied to South America as oil burners. They had extra water capacity as well as oil burning equipment. They were supplied with a special small additional boiler for turning over the engine to start it. They were required for a steam tramway, and so wheels and motion were enclosed. There is a fine maker’s photograph of No 1041 INDAYA.

Wrens were exported to quarries and mines over the world.

The First World War

From 1914-18, Wrens did ‘War Service’ though mainly for construction works, and almost always in 2’ gauge. Three went to the Falkland Islands, then a Naval Coaling station and no 2462 was sent to Archangel, Russia. The ‘new type’ Wren had just been introduced; it is fair to suggest that the War Office encouraged the introduction of the cheaper design feature.

Another KS introduction of the time was the ‘Joffre’ 0-3-0T locomotive, ordered early in the War and built to French specifications in 60cm gauge.

As the author of Colonel Péchot: Tracks To The Trenches, I have always believed that the French military railways – designed in the 19^th century by Prosper Péchot – heavily influenced subsequent military railways of friend and foe.  Before the First World War, British ‘siege railways’ (ie portable railways for field duties) were all 2’6” gauge. As early as 1915, the Army became alive to the merits of 2’/60cm gauge, and when the War Department Light Railways were brought into official being in 1916, 60cm was the uncontroversial choice of gauge. In 1915, Wrens were being sent to Ripon and Catterick for construction work at Army sites.

No 3105 – 2’ gauge – was despatched in February 1918 and was used in constructing Kidbrooke Aerodrome near Birmingham. Circa 1935 it was purchased by the Leighton Buzzard Brick Co and photographs of the time show that it bore the HAIG nameplate.

Post War

After WW1, K,S & Co went into standard gauge manufacture. The trade received a boost from the grouping of British railways, receiving (for them) large orders from the GWR and LMS. From the late 20s, K,S went into the manufacture of diesel locomotives, though development was stopped when the company went into receivership.

PIXIE no 4560 photographed at the Leighton Buzzard Light Railway by Malcolm Wright in 1980

Narrow gauge was not forgotten. Between 1922 and 23, a number of Wrens were delivered to R.H. Neal and Co for sewage construction works (we believe). Several were sold to Devon County Council for similar construction duties eg at the Wilminstone quarry. Some have survived. No 4250 – known these days as LORNA DOONE – was preserved by Birmingham Museum and Art Gallery. No 4560 – PIXIE – was preserved by the Industrial Railway Society and then passed to the Leighton Buzzard Light Railway to be brought back into working order.  From 1969 she has been a well-loved fixture. Another Wren, No 3114, was rescued by Alan Maund in 1959.

Hunslet took over the ‘goodwill’ of Kerr, Stuart when it closed in 1930. Hunslet based their range of diesel locomotives on K,S originals. In addition, four more Wrens were made – also to 2’ gauge. 

PIXIE, also photographed at Leighton Buzzard by Malcolm Wright

If you like your Wrens ‘stuffed and mounted’, the National Railway Museum, York has one, as does Birmingham.  This is how Malcolm prefers his National Treasures – safe from wear and tear. If, like me, you prefer to see them at work, PIXIE and PETER PAN still come out in steam on occasion. See below. Don’t intervene in arguments between man and wife, but perhaps a compromise position is best. The originals should be preserved, but good replicas should be put into steam as has been done with K,S Tattoo class  no 4047. A replica was created to work on the preserved Corris railway.

A Wren abroad

There is, nothing to compare with the delight of snapping a Wren survival in far-flung parts. In 1971, Basil Roberts saw a Wren, among other locomotives at the Srimaharacha timber works at Si (Sri) Racha, Thailand, about two hours from Bangkok. It was also seen by C.M. Jackson in 1984. He made the short walk through the port to the mill. By this time, the locomotives, including a Wren, a Brush 0-6-0, a Hudswell Clarke 0-4-2 and an Orenstein and Koppel 0-6-0, were laid up behind a fence and were clearly in retirement. The line had been built from the mill into the forest, in 1906, as Jackson was told. The gauge was 759mm gauge. No-one was quite sure when the locomotives were last used; before the date of the visit by Basil Roberts – we believe.

At the time of Jackson’s visit, timber was brought to the mill by lorries but he did see railways being used onsite.  Some diesel locomotives were at work within the factory, and small rolling stock, both trolley-type and slat-sided vehicles. Subsequent research showed the old railway line on an old Admiralty chart, running at least 10 miles/16 km into the hills. Wilf Simms also visited Srimaharacha that year and did some more rooting around.

All visitors have been told ‘Yes, you may look, but no, the locomotives are not for sale’

Kerr, Stuart nameplate courtesy of Armley Industrial Museum. This Wren, maker's number 2462 was destined for Archangel. This batch, nos 2458 to 2465 was among the most far-travelled of the Wrens, another going to Burma. This batch was also notable for being the first of the 'new' type.

Wrens at home

We had our own encounter with a Wren. This was PIXIE at Leighton Buzzard in 1980. The line is based at Page’s Park, Leighton Buzzard, and roughly 3 ½ miles long, taking in both urban and rural running. It had been originally opened as a quarry railway At the time it was possible to savour the a semi-industrial landscape as a sand pit still existed. In a little train headed by a PIXIE, we started out of Pages Park and then up a hill. Then steeply down and past modern industrial Leighton Buzzard. Past a certain celebrated roof-tile factory, there is a steep run up Marley’s Bank and then into Bedfordshire countryside, now housing. More fields, then a factory, then sand-pit workings marked the limit of the line.

Another 16mm Wrightscale model Wren, in red. 

Another Wren at work is PETER PAN at the North of England Open Air Museum, Beamish, Stanley, Co Durham. If you can’t get there, some nice u-tube shots show him at work doing what a Wren does best -  hauling skips!

Armley Industrial Museum, now known as the Leeds Industrial Museum, holds a treasury of Kerr Stuart records. Worth a visit!

Further reading: INDUSTRIAL RAILWAY RECORD no 5. This was published by the Birmingham Locomotive Club, now known as the Industrial Railway Society.

INDUSTRIAL RAILWAY RECORD no 104 (among others)

CONTINENTAL RAILWAY JOURNALs for 1996

Leighton Buzzard Light Railway Guide Book

Grace’s Guide